1. Field of the Invention
The present invention relates to a joint structure for joining a fluid supply pump with a fluid supply pipe, and more particularly relates to a joint structure suitably applicable for use with a fuel supply pump in a vehicle.
2. Description of the Prior Art
In many cases, the fuel supply pump in a vehicle is provided within the fuel tank. One example of a fuel supply pump for a vehicle is shown in FIG. 2.
As shown in FIG. 2, a fuel supply pump 3 is disposed within a fuel tank 1 is vertically is vertically The pump housing of the pump 3 is composed of a sealed cylindrical body. The pump 3 is supported by a supporting member 5 provided within the fuel tank 1 through a well known rubber bushing 4. The lower end of the pump 3 is joined with a fuel inlet pipe 15 having a filter 151. From the upper end surface of the pump 3 centrally projects a fuel outlet pipe 6.
The upper wall of the fuel tank 1, to which a tip end of the fuel outlet pipe 6 is opposed is upwardly expanded. A cylindrical joint member 12 is provided so as to penetrate the expanded portion of the upper wall of the fuel tank 1. The lower end of the cylindrical joint member 12 is opposed to the tip end of the outlet pipe 6 at a position close thereto. The upper end of the joint member 12, which is exposed to the outside of the fuel tank 1 is joined with one end of a fuel supply pipe 8 leading to an engine (not shown).
The outlet pipe 6 is joined with the joint member 12 by means of a rubber pipe 13 and around each of both ends of the rubber pipe 13 is fitted a metallic clamp 14.
The outlet pressure of the fuel supply pump normally reaches a maximum pressure which is over 2 Kg/cm.sup.2. For obtaining a sufficiently high sealing property, the close contact area between the rubber pipe 13 and each of the outlet pipe 6 and the joint member 12 must be made large by increasing the length of each of the outlet pipe 6 and the joint member 12.
Due to recent trends in automotive design in which the height H of the fuel tank tends to be strictly limited for enlarging the space of the passenger compartment, it is difficult to obtain a sufficiently long space for the outlet pipe 6 and the joint member 12.
Under the above circumstances, it is proposed that the contact pressure of the rubber pipe 13 with the outlet pipe 6 or the joint member 12 is increased by decreasing the inner diameter of the rubber pipe. But, this method is troublesome in assembling.